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845篇 您的检索式:作者名="Jianping Zhang"
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1A complete sequence and comparative analysis of a SARS-associated virus(Isolate BJ01)显示文摘The genome sequence of the Severe Acute Respiratory Syndrome (SARS)-associated virus provides essential information for the identification of pathogen(s), exploration of etiology and evolution, interpretation of transmission and pathogenesis, development of diagnostics, prevention by future vaccination, and treatment by developing new drugs. We report the complete genome sequence and comparative analysis of an isolate (BJ01) of the coronavirus that has been recognized as a pathogen for SARS. The genome is 29725 nt in size and has 11 ORFs (Open Reading Frames). It is composed of a stable region encoding an RNA-dependent RNA polymerase (composed of 2 ORFs) and a variable region representing 4 CDSs (coding sequences) for viral structural genes (the S, E, M, N proteins) and 5 PUPs (putative uncharacterized proteins). Its gene order is identical to that of other known coronaviruses. The sequence alignment with all known RNA viruses places this virus as a member in the family of Coronaviridae. Thirty putative substitutions have been identified by comparative analysis of the 5 SARS- associated virus genome sequences in GenBank. Fifteen of them lead to possible amino acid changes (non-synonymous mutations) in the proteins. Three amino acid changes, with predicted alteration of physical and chemical features, have been detected in the S protein that is postulated to beinvolved in the immunoreactions between the virus and its host. Two amino acid changes have been detected in the Mprotein, which could be related to viral envelope formation. Phylogenetic analysis suggests the possibility of non-human origin of the SARS-associated viruses but provides noevidence that they are man-made. Further efforts should focus on identifying the etiology of the SARS-associated virus and ruling out conclusively the existence of otherpossible SARS-related pathogen(s).QIN E'de ZHU Qingyu YU Man FAN Baochang CHANG Guohui SI Bingyin YANG Bao PENG Wenming JIANG Tao LIU Bohua DENG Yongqiang LIU Hong ZHANG Yu WANG Cui LI Yuquan GAN Yonghua LI Xiaoyu L Fushuang TAN Gang CAO Wuchun, YANG Ruifu Institute of Microbiology and Epidemiology, Chinese Academy of Military Medical Sciences, Beijing 100071, China WANG Jian, LI Wei, XU Zuyuan, LI Yan, WU Qingfa, LIN Wei, CHEN Weijun, TANG Lin, DENG Yajun, HAN Yujun, LI Changfeng, LEI Meng, LI Guoqing, LI Wenjie, L Hong, SHI Jianping, TONG Zongzhong, ZHANG Feng, LI Songgang, LIU Bin, LIU Siqi, DONG Wei, WANG Jun, Gane K-S Wong, YU Jun & YANG Huanming* Beijing Genomics Institute, Chinese Academy of Sciences, Beijing 101300 National Center for Genome Information, Beijing 101300, China 2003Chinese Science Bulletin2003,48,10:121
2Relocation of the M8.0 Wenchuan earthquake and its aftershock sequence显示文摘We relocated M8.0 Wenchuan earthquake and 2706 aftershocks with M≥2.0 using double-difference algorithm and obtained relocations of 2553 events. To reduce the influence of lateral variation in crustal and upper mantle velocity structure, we used different velocity models for the east and west side of Longmenshan fault zone. In the relocation process, we added seismic data from portable seismic sta-tions close to the shocks to constrain focal depths. The precisions in E-W, N-S, and U-D directions after relocation are 0.6, 0.7, and 2.5 km respectively. The relocation results show that the aftershock epi-centers of Wenchuan earthquake were distributed in NE-SW direction, with a total length of about 330 km. The aftershocks were concentrated on the west side of the central fault of Longmenshan fault zone, excluding those on the north of Qingchuan, which obviously deviated from the surface fault and passed through Pingwu-Qingchuan fault in the north. The dominant focal depths of the aftershocks are between 5 and 20 km, the average depth is 13.3 km, and the depth of the relocated main shock is 16.0 km. The depth profile reveals that focal depth distribution in some of the areas is characterized by high-angle westward dipping. The rupture mode of the main shock features reverse faulting in the south, with a large strike-slip component in the north.HUANG Yuan WU JianPing ZHANG TianZhong ZHANG DongNing 2008Science China Earth Sciences2008,51,12:64
3The Tartary Buckwheat Genome Provides Insights into Rutin Biosynthesis and Abiotic Stress Tolerance显示文摘Zhang, Lijun Li, Xiuxiu Ma, Bin Gao, Qiang Du, Huilong Han, Yuanhuai Li, Yan Cao, Yinghao Qi, Ming Zhu, Yaxin Lu, Hongwei Ma, Mingchuan Liu, Longlong Zhou, Jianping Nan, Chenghu Qin, Yongjun Wang, Jun Cui, Lin Liu, Huimin Liang, Chengzhi Qiao, Zhijun 2017Molecular Plant2017,10,9:53
4Zircon U-Pb age and Hf isotope of Quanyishang A-type granite in Yichang: Signification for the Yangtze continental cratonization in Paleoproterozoic显示文摘Zircon U-Pb age and Hf isotope, and major and trace element compositions were reported for granite at Quanyishang, which intruded into the Kongling complex in Yichang, Hubei Province. The results show that the Quanyishang granite is rich in silicon and alkalis but poor in calcium and magnesium, and displays enrichment in Ga, Y, Zr, Nb but depletion in Sr and Ba, exhibiting the post-orogenic A-type affinity. 90% zircons from the granite are concordant, and give a middle Paleoproterozoic magmatic crystallization age (mean 1854 Ma). Initial Hf isotope ratios (176Hf/177Hf)i of the middle Paleoproterozoic zircons range from 0.280863 to 0.281134 and they have negative εHf(t) values with a minimum of -26.3. These zircons give the depleted mantle model ages (TDM) of 2.9―3.3 Ga (mean 3.0 Ga), and the average crustal model ages (Tcrust) of 3.6―4.2 Ga (mean 3.8 Ga). A Mesoarchean grain with 207Pb/206Pb age of 2859 Ma has a slightly high TDM (3.4 Ga) but similar Tcrust (3.8 Ga) to the Paleoproterozoic zircons. All these data suggest that the source materials of the Quanyishang A-type granite are unusually old, at least ≥2.9 Ga (even Eoarchean). The event of crustal remelting, which resulted in the formation of the Quanyishang granite in the middle Paleoproterozoic, recorded the cratonization of the Yangtze conti- nent. The process may have relation to the extension and collapse of the deep crust with Archean ages, in response to the transition stage of the assembly and breakup of the Columbia supercontinent.XIONG Qing HENG JianPing YU ChunMei SU YuPing TANG HuaYun ZHANG ZhiHai 2009Chinese Science Bulletin2009,54,3:46
5Cryospheric Science: research framework and disciplinary system显示文摘Cryospheric changes and their impacts have received increasing concern, extending the research to include the interactions between earth spheres and the impacts of and social adaptation to cryospheric changes. As a result, Cryospheric Science is rapidly developing. However, the research framework of Cryospheric Science has not completely been set up, and the intension and extension of Cryospheric Science are unclear.Following a literature review, the research framework for Cryospheric Science and the discipline components are analysed in this paper. We consider that Cryospheric Science is an inevitable product of international research on the earth and environmental changes as well as on human sustainable development. It will not only strengthen the linkage between the cryosphere and other earth spheres by deepening traditional research areas, but will also bring more focus on the critical roles of the cryosphere in interactions between earth spheres, and will enhance the relationship between cryospheric change and climate, ecology, hydrology, surface environment and sustainable development. The disciplinary tree of Cryospheric Science is developed following the mainstream of change-impacts adaptation. The disciplines of Cryospheric Science were teased out against characteristics of traditional branches and the developing interdisciplinary branches of cryosphere elements, which will provide reference to Cryospheric Science as it systematically grows to maturity.Dahe Qin Yongjian Ding Cunde Xiao Shichang Kang Jianwen Ren Jianping Yang Shiqiang Zhang 2018National Science Review2018,5,2:42
6Aerosol and boundary-layer interactions and impact on air quality显示文摘Air quality is concerned with pollutants in both the gas phase and solid or liquid phases. The latter are referred to as aerosols, which are multifaceted agents affecting air quality, weather and climate through many mechanisms. Unlike gas pollutants, aerosols interact strongly with meteorological variables with the strongest interactions taking place in the planetary boundary layer(PBL). The PBL hosting the bulk of aerosols in the lower atmosphere is affected by aerosol radiative effects. Both aerosol scattering and absorption reduce the amount of solar radiation reaching the ground and thus reduce the sensible heat fluxes that drive the diurnal evolution of the PBL. Moreover, aerosols can increase atmospheric stability by inducing a temperature inversion as a result of both scattering and absorption of solar radiation, which suppresses dispersion of pollutants and leads to further increases in aerosol concentration in the lower PBL.Such positive feedback is especially strong during severe pollution events. Knowledge of the PBL is thus crucial for understanding the interactions between air pollution and meteorology. A key question is how the diurnal evolution of the PBL interacts with aerosols, especially in vertical directions, and affects air quality.We review the major advances in aerosol measurements, PBL processes and their interactions with each other through complex feedback mechanisms, and highlight the priorities for future studies.Zhanqing Li Jianping Guo Aijun Ding Hong Liao Jianjun Liu Yele Sun Tijian Wang Huiwen Xue Hongsheng Zhang Bin Zhu 2017National Science Review2017,4,6:37
7Phase II clinical trial using camrelizumab combined with apatinib and chemotherapy as the first-line treatment of advanced esophageal squamous cell carcinoma显示文摘Background:Effective therapeutic options are limited for patients with advanced esophageal squamous cell carcinoma(ESCC).The incorporation of an immune checkpoint inhibitor and a molecular anti-angiogenic agent into the commonly adopted chemotherapy may produce synergistic effects.Therefore,we aimed to investigate the efficacy and safety of camrelizumab plus apatinib combined with chemotherapy as the first-line treatment of advanced ESCC.Methods:In this single-arm prospective phase II trial,patients with unresectable locally advanced or recurrent/metastatic ESCC received camrelizumab 200 mg,liposomal paclitaxel 150 mg/m2,and nedaplatin 50 mg/m2 on day 1,and apatinib 250 mg on days 1-14.The treatments were repeated every 14 days for up to 9 cycles,followed by maintenance therapy with camrelizumab and apatinib.The primary endpoint was objective response rate(ORR)according to the Response Evaluation Criteria in Solid Tumors(version 1.1).Secondary endpoints included disease control rate(DCR),progression-free survival(PFS),overall survival(OS),and safety.Results:We enrolled 30 patients between August 7,2018 and February 23,2019.The median follow-up was 24.98 months(95%confidence interval[CI]:23.05-26.16 months).The centrally assessed ORR was 80.0%(95%CI:61.4%-92.3%),with a median duration of response of 9.77 months(range:1.54 to 24.82+months).The DCR reached 96.7%(95%CI:82.8%-99.9%).The median PFS was 6.85 months(95%CI:4.46-14.20 months),and the median OS was 19.43 months(95%CI:9.93 months–not reached).The most common grade 3-4 treatmentrelated adverse events(AEs)were leukopenia(83.3%),neutropenia(60.0%),and increased aspartate aminotransferase level(26.7%).Treatment-related serious AEs included febrile neutropenia,leukopenia,and anorexia in one patient(3.3%),and single cases of increased blood bilirubin level(3.3%)and toxic epidermal necrolysis(3.3%).No treatment-related deaths occurred.Conclusions:Camrelizumab plus apatinib combined with liposomal paclitaxel and nedaplatin as first-line treatment demonstrated feasible anti-tumor activity and manageable safety in patients with advanced ESCC.Randomized trials to evaluate this new combination strategy are warranted.Trial registration:This trial was registered on July 27,2018,at ClinicalTrials.gov(identifier:NCT03603756).Bo Zhang Ling Qi Xi Wang Jianping Xu Yun Liu Lan Mu Xingyuan Wang Lidan Bai Jing Huang 2020Cancer Communications2020,40,12:38
8Therapeutic effects of the artemisinin analog SM934 on lupus-prone MRLIIpr mice via inhibition of TLR-triggered B-cell activation and plasma cell formation显示文摘我们以前报导了那 SM934,水溶性的 artemisinin 衍生物,是在鼠科的豺狼座模型的一个可行处理。在当前的学习,我们进一步在豺狼座容易的 MRL/lpr 老鼠上调查了 SM934 的修改剂量政体的治疗学的效果并且在 B 房间回答上探索了它的效果,在全身的豺狼座 erythematosus (SLE ) 的一个中央病原的事件。当口头上地管理了时两次每日, SM934 显著地延长了 MRL/lpr 老鼠的寿命,改善 lymphadenopathy 症状并且减少浆液的层次反原子的抗体(言论集) 并且病原的 cytokines IL-6, IL-10 和 IL-21。而且, SM934 处理由增加静止 B 房间数字在 MRL/lpr 老鼠的怒气恢复了 B 房间分隔空间,维持幼芽的中心 B 房间数字,减少激活的 B 房间数字和减少的血浆房间(PC ) 数字。前 vivo, SM934 压制了触发的像使用费的受体(TLR ) B 房间的激活和增长,以及抗体分泌物。而且,现在的学习证明 SM934 由 downregulating TLR7/9 mRNA 表示, MyD88 蛋白质表示和 NF-κ 防碍 B 房间内在的小径; B phosphorylation。在人的外部血 mononuclear 房间(PBMC ) ,与在 MRL/lpr 鼠标的结果一致, SM934 禁止了联系 TLR 的 B 房间激活和 PC 区别。在结论, SM934 的两次每日的 dosing 政体由压制 B 房间激活和血浆房间形成在豺狼座容易的 MRL/lpr 老鼠上有治疗学的效果。Yanwei Wu Shijun He Bingxin Bai Luyao Zhang Lu Xue Zemin Lin Xiaoqian Yang Fenghua Zhu Peilan He Wei Tang Jianping Zuo 2016Cellular & Molecular Immunology2016,13,3:31
9The state-of-the-art of the China Seismo-Electromagnetic Satellite mission显示文摘The China Seismo-Electromagnetic Satellite(CSES) mission was proposed in 2003 and approved in 2013 after ten years' scientific and engineering demonstrations. To meet the requirement of scientific objectives, the satellite is designed to be in a sunsynchronous orbit with an altitude of 507 km and descending node time of 14:00 LT. The CSES satellite carries 8 instruments,including search-coil magnetometer(SCM), electric field detector(EFD), high precision magnetometer(HPM), GNSS occultation receiver(GOR), plasma analyzer package(PAP), langmuir probe(LAP), high energetic particle package(HEPP) and detector(HEPD), and tri-band beacon(TBB), among which HEPD is provided by Italian Space Agency. The CSES satellite was launched successfully on February 2, 2018, and is planned to operate for 5 years. The CSES mission is the first satellite in China to measure geophysical fields, which will have a lot of application prospects in the study of seismology, geophysics, space sciences, and so on.SHEN XuHui ZHANG XueMin YUAN ShiGeng WANG LanWei CAO JinBin HUANG JianPing ZHU Xing Hong PIERGIORGIO Picozzo DAI JianPing 2018Science China(Technological Sciences)2018,61,5:33
105-Hydroxymethylcytosine signatures in circulating cell-free DNA as diagnostic biomarkers for human cancers显示文摘象 5-methylcytosine (5mC ) 和 5-hydroxymethylcytosine (5hmC ) 那样的 DNA 修正是知道在哺乳动物影响全球基因表示的 epigenetic 标记。在人的染色体,与基因表示的靠近的关联和高化学的稳定性给他们的流行,这些 DNA epigenetic 标记能为癌症用作理想的 biomarkers 诊断。利用一种高度敏感、选择的化学标记技术,我们这里报导在传播没有房间的 DNA ( cfDNA )并且在从最近与 colorectal 诊断的 260 个病人的一个队收集的配对的肿瘤和邻近的纸巾的 genomic DNA ( gDNA )的 5hmC 的染色体宽的介绍,胃,胰腺,从 90 个健康个人的肝或甲状腺癌症和正常纸巾。5hmC 主要在与开的染色质和容许的 histone 修正重合的 transcriptionally 活跃的区域被散布。柔韧的联系癌症的 5hmC 签名在 cfDNA 被识别为特定的癌症类型是特征的。传播 cfDNA 的 5hmC 底 biomarkers colorectal 和胃的癌症是高度预兆的并且比常规 biomarkers 优异并且比得上从织物活体检视的 5hmC biomarkers。因此,这新策略能从血样品的分析为癌症的诊断和预后导致有效、最低限度地侵略的方法的发展。Wenshuai Li Xu Zhang Xingyu Lu Lei You Yanqun Song Zhongguang Luo Jun Zhang Ji Nie Wanwei Zheng Diannan Xu Yaping Wang Yuanqiang Dong Shulin Yu Jun Hong Jianping Shi Hankun Hao Fen Luo Luchun Hua Peng Wang Xiaoping Qian Fang Yuan Lianhuan Wei Ming Cui Taiping Zhang Quan Liao Menghua Dai Ziwen Liu Ge Chen Katherine Meckel Sarbani Adhikari Guifang Jia Marc B Bissonnette Xinxiang Zhang Yupei Zhao Wei Zhang Chuan He Jie Liu 2017Cell Research2017,27,10:30
11Seafloor hydrothermal activity and polymetallic sulfide exploration on the southwest Indian ridge显示文摘Polymetallic sulfides have attracted more attentions,which are regarded as one of the potential seabed mineral resources for their high grade of precious metal elements such as Cu,Zn,Pb,Au,and Ag.Since2007,there are four China dayang cruises(CDCs)with eight legs totally,which have been carried out to investigate polymetallic sulfides on the southwest Indian ridge(SWIR),and eight hydrothermal vents have been found.In2011,the China Ocean Mineral Resources Research and Development Association(COMRA)and International Seabed Authority(ISA)signed a 15-year contract for exploration for polymetallic sulfides located on the SWIR between 46°S and 53°S.The area allocated to the COMRA is approximately 10,000 km2.In this paper,we review the recent research advances about hydrothermal activity of the SWIR by the CDCs.As for the sulfides exploration in the future,some aspects should be emphasized,such as the controlling factors of sulfide mineralization on the SWIR,prospecting methods of inactive and buried sulfide deposits,sulfides resources assessment method,and the nearbottom sulfides exploration technology systems.Chunhui Tao Huaiming Li Xiaobing Jin Jianping Zhou Tao Wu Yonghua He Xianming Deng Chunhua Gu Guoyin Zhang Weiyong Liu 2014Chinese Science Bulletin2014,59,19:25
12Fundamental geological elements for the occurrence of Chinese marine oil and gas accumulations显示文摘The Paleozoic strata in the Tarim Basin, Sichuan Basin and Ordos Basin are the major targets for marine petroleum exploration, with developed high quality hydrocarbon, mainly argillite. The deep burial of these source rocks suggests that they mainly develop gas instead of oil. But different maturities of organic matter may lead to different hydrocarbon facies. Through thermochemical sulfate reduction (TSR), the hydrocarbon in the carbonate rocks may undergo a process of pyrolytic cracking and be catalyzed into gases. The marine reservoirs mainly consist of carbonate and clastic rocks, and the former is controlled by sedimentary facies, dolomitization, solution, TSR and cracking. The multiphase tectonic cycling develops multiple source-reservoir-cap combinations and diversified types of traps and reservoirs, featuring multiphase reservoir formation, mainly late-phase formation or consolidation. Palaeo-uplifts play a controlling role in hydrocarbon accumulation. Differences in major source rocks in the three basins lead to different locations of oil-gas accumulation layers, different types and patterns of reservoirs and different features of reservoir formation.ZHANG ShuiChang LIANG DiGang ZHU GuangYou ZHANG XingYang ZHANG BaoMin CHEN JianPing ZHANG Bin 2007Chinese Science Bulletin2007,52,A01:22
13Robust Transcriptional Activation in Plants Using Multiplexed CRISPR-Act2.0 and mTALE-Act Systems显示文摘为内长的基因的柔韧的 transcriptional 激活的用户友好的工具高度在植物被要求。我们以前显示出那由撤销联系 CRISPR 的蛋白质组成的一个 dCas9-VP64 系统(dCas9 ) 9 与四辆双人脚踏车熔化了使活跃之物 VP16 (VP64 ) 能被用于的 transcriptional 的重复在植物的内长的基因的 transcriptional 激活。在这研究,我们在植物为提高的 transcriptional 激活开发了向量系统的第二代。我们为基于 dCas9 的 transcriptional 激活测试了多重策略,并且由 dCas9 和产出的修改指南 RNA 支架 gRNA2.0 (指明的 CRISPR-Act2.0 ) 发现那 VP64 的同时的招募更强壮的 transcriptional 激活比 dCas9-VP64 系统。而且,我们开发了复合抄写为在植物的多达四基因的同时的激活的像使活跃之物的受动器激活(mTALE 行为) 系统。我们的结果建议 mTALE 行为是比在测试的大多数情况中的 CRISPR-Act2.0 甚至更有效的。另外,我们用积极反馈环探索了织物特定的基因激活。有趣地,我们的学习比当由激活探针使不安时,其它可以引起目标基因 silencing 到 transcriptional 激活,和紧调整的基因的表明某些内长的基因是更顺从的。因此,这些新工具能被用来调查基因规章的网络和他们的控制机制。复合 CRISPR-Act2.0 和 mTALE 行为系统的汇编是两个基于优化并且克隆策略的 PCR 独立的金门和网关,它将在 dicots 和 monocots 便于 transcriptional 激活应用程序。Levi G. Lowder Jianping Zhou Yingxiao Zhang Aimee Malzahn Zhaohui Zhong Tzung-Fu Hsieh Daniel F. Voytas Yong Zhang Yiping Qi 2018Molecular Plant2018,11,2:19
14A review of ecological restoration techniques in fluvial rivers显示文摘Rivers play an important role in people's living and agricultural production,however,intense human activities have broken the original ecological balance,and affected structures and functions of the river ecosystem.To restore the damaged river ecosystem back to a healthy status,effective ecological restoration measures need to be implemented.The main problems that the damaged rivers face are either the locally altered hydrological processes affected by construction of hydraulic facilities,or the deterioration of water quality resulted from pollution emissions,or both.In this study,ecological restoration techniques of the rivers affected by engineering control or pollution are reviewed respectively.In addition,three kinds of methods,i.e.physical,chemical and biological-ecological methods are introduced in details for the rivers affected by water pollution.At present,the development of river restoration techniques shows the following trends:1) the scale of ecological restoration is becoming larger;2) ecological restoration measures are required to meet multiple objectives;and 3) the management of water environment is changing from water quality management to aquatic ecosystem management.Baozhu Pan Jianping Yuan Xinhua Zhang Zhaoyin Wang Jiao Chen Jinyou Lu Wenjun Yang Zhiwei Li Na Zhao Mengzhen Xu 2016International Journal of Sediment Research2016,31,2:18
15Assessment of the GPM and TRMM Precipitation Products Using the Rain Gauge Network over the Tibetan Plateau显示文摘Using high-quality hourly observations from national-level ground-based stations, the satellite-based rainfall products from both the Global Precipitation Measurement(GPM) Integrated Multisatellit E Retrievals for GPM(IMERG) and its predecessor, the Tropical Rainfall Measuring Mission(TRMM) Multi-satellite Precipitation Analysis(TMPA), are statistically evaluated over the Tibetan Plateau(TP), with an emphasis on the diurnal variation.The results indicate that:(1) the half-hourly IMERG rainfall product can explicitly describe the diurnal variation over the TP, but with discrepancies in the timing of the greatest precipitation intensity and an overestimation of the maximum rainfall intensity over the whole TP. In addition, the performance of IMERG on the hourly timescale, in terms of the correlation coefficient and relative bias, is different for regions with sea level height below or above 3500 m;(2) the IMERG products, having higher correlation and lower root-mean-square error, perform better than the TMPA products on the daily and monthly timescales; and(3) the detection ability of IMERG is superior to that of TMPA, as corroborated by a higher Hanssen and Kuipers score, a higher probability of detection, a lower false alarm ratio, and a lower bias. Compared to TMPA, the IMERG products ameliorate the overestimation across the TP. In conclusion,GPM IMERG is superior to TRMM TMPA over the TP on multiple timescales.Sijia ZHANG Donghai WANG Zhengkun QIN Yaoyao ZHENG Jianping GUO 2018Journal of Meteorological Research2018,32,2:18
16Rattle-Type Silica Colloidal Particles Prepared by a Surface- Protected Etching Process显示文摘This paper explores the capability of the“surface-protected etching”process for the creation of rattle-type SiO_(2)@void@SiO_(2) colloidal structures featuring a mesoporous silica shell and a mesoporous movable silica core.The surface-protected etching process involves stabilization of the particle surface using a polymer ligand,and then selective etching of the interior to form hollow structures.In this paper,this strategy has been extended to the formation of rattle-like structures by etching SiO_(2)@SiO_(2) core shell particles which are synthesized by a two-step sol gel process.The key is to introduce a protecting polymer of polyvinylpyrrolidone(PVP)to the surface of both core and shell in order to tailor their relative stability against chemical etching.Upon reacting with NaOH,the outer layer silica becomes a hollow shell as only the surface layer is protected by PVP and the interior is removed,while the core remains its original size thanks to the protection of PVP on its surface.This process can be carried out at room temperature without the need of additional templates or complicated heterogeneous coating procedures.The etching process also results in the rattle-type colloids having mesoscale pores with two distinct average sizes.In our demonstration of a model drug delivery process,such mesoporous structures show an interesting two-step elution profile which is believed to be related to the unique porous rattle structures.Qiao Zhang Jianping Ge James Goebl Yongxing Hu Zhenda Lu Yadong Yin 2009Nano Research2009,2,7:18
17Eco-environment range in the source regions of the Yangtze and Yellow rivers显示文摘Based on geographical and hydrological extents delimited, four principles are identified, as the bases for delineating the ranges of the source regions of the Yangtze and Yellow rivers in the paper. According to the comprehensive analysis of topographical characteristics, climate conditions, vegetation distribution and hydrological features, the source region ranges for eco-environmental study are defined. The eastern boundary point is Dari hydrological station in the upper reach of the Yellow River. The watershed above Dari hydrological station is the source region of the Yellow River which drains an area of 4.49×10 4 km 2 . Natural environment is characterized by the major topographical types of plateau lakes and marshland, gentle landforms, alpine cold semi-arid climate, and steppe and meadow vegetation in the source region of the Yellow River. The eastern boundary point is the convergent site of the Nieqiaqu and the Tongtian River in the upstream of the Yangtze River. The watershed above the convergent site is the source region of the Yangtze River, with a watershed area of 12.24×10 4 km 2 . Hills and alpine plain topography, gentle terrain, alpine cold arid and semi-arid climate, and alpine cold grassland and meadow are natural conditions in the source region of the Yangtze River.DING Yongjian,YANG Jianping,LIU Shiyin,CHEN Rensheng,WANG Genxu,SHEN Yongping,WANG Jian,XIE Changwei,ZHANG Shiqing(Cold and Arid Regions Environmental and Engineering Research Institute, CAS, Lanzhou 730000, China) 2003Journal of Geographical Sciences2003,13,2:18
18Design of Robot Welding Seam Tracking System with Structured Light Vision显示文摘Robot welding is an important developing direction of welding automation and intelligentization, and automatic seam tracking technology is one of principal research domains. Nowadays, seam tracking system with structured light vision becomes a hot research. Structured light vision seam tracking products abroad are generally very expensive and can only be applied on special occasions. In China, the research of structured light vision seam tracking system is still just on the stage of experiments. A robot real-time seam tracking system with line structured light vision is designed. The hardware system is set up, a filtering method for line structure seam image is improved, and compared with common filtering, it has better effect and characteristic of real time. Two methods, fast template matching and fast Hough transform, to recognize the image coordinates of seam center are improved. Two new image recognition methods, structure element matching and corner detecting, are proposed. The comparison of seam image recognition shows that fast template matching and corner detecting are more precise and stable than the other two methods, and corner detecting is the best in real time. A simultaneous calibration for camera parameters and robot hand-eye is also proposed, and calculation shows that the calibration is effective and feasible. The robot seam tracking tests for linear and folded lap-joint are performed, which are based on the above four image recognition methods, and the results indicate that four image recognition methods are all applicable to real-time seam tracking, and the whole system sufficed for the requirements of real-time seam tracking. Automatic seam tracking with line structured light vision is feasible and has good versatility.LIU Suyi WANG Guorong ZHANG Hua JIA Jianping 2010Chinese Journal of Mechanical Engineering2010,23,4:17
19Advances in studying interactions between aerosols and monsoon in China显示文摘Scientific issues relevant to interactions between aerosols and the Asian monsoon climate were discussed and evaluated at the 33 rd 'Forum of Science and Technology Frontiers' sponsored by the Department of Earth Sciences at the Chinese Academy of Sciences. Major results are summarized in this paper. The East Asian monsoon directly affects aerosol transport and provides a favorable background circulation for the occurrence and development of persistent fog-haze weather. Spatial features of aerosol transport and distribution are also influenced by the East Asian monsoon on seasonal, inter-annual, and decadal scales. High moisture levels in monsoon regions also affect aerosol optical and radiative properties. Observation analyses indicate that cloud physical properties and precipitation are significantly affected by aerosols in China with aerosols likely suppressing local light and moderate rainfall, and intensifying heavy rainfall in southeast coastal regions. However, the detailed mechanisms behind this pattern still need further exploration. The decadal variation in the East Asian monsoon strongly affects aerosol concentrations and their spatial patterns. The weakening monsoon circulation in recent decades has likely helped to increase regional aerosol concentrations. The substantial increase in Chinese air pollutants has likely decreased the temperature difference between land and sea, which favors intensification of the weakening monsoon circulation. Constructive suggestions regarding future studies on aerosols and monsoons were proposed in this forum and key uncertain issues were also discussed.WU GuoXiong LI ZhanQing FU CongBin ZHANG XiaoYe ZHANG RenYi ZHANG RenHe ZHOU TianJun LI JianPing LI JianDong ZHOU DeGang WU Liang ZHOU LianTong HE Bian HUANG RongHui 2016Science China Earth Sciences2016,59,1:16
20EFFECTS OF SPLITTER BLADES ON THE LAW OF INNER FLOW WITHIN CENTRIFUGAL PUMP IMPELLER显示文摘有 splitter 片的离心的泵 impeller 的内部流动地上的分析被数字模拟执行。把分析基于这,增加泵头和效率的原则被讨论。新结果从骚乱动能和相对速度分发的分析被获得:第一, splitter 片的无理的长度或偏差设计可以在 impeller 隧道引起大狂暴的变化,它在 impeller 插头流动的稳定性上有大效果;第二,流动分离的出现能被减少或从片装载的分析与 splitter 推迟了片,这被发现;第三,改革“喷气醒来”的结构上的 splitter 片的效果在不同流动剖面图从相对速度分发被解释,它在 impeller 显示出流动过程。内部流动分析验证表演测试结果和 PIV 测试的结果。YUAN Shouqi ZHANG Jinfeng YUAN Jianping HE Youshi FU Yuedeng 2007Chinese Journal of Mechanical Engineering2007,20,5:16
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